This opinion is pretty behind the times. Like, two or three years behind the times.

Just a few examples of games that make the majority of their funds from virtual goods:

League of Legends(the most played game worldwide right now) DotA 2/Team Fortress 2 Maple Story Planetside 2

It's actually generating a huge amount of cash. WoW just wasn't ever set up for it, and still to this day sells around a total of 15-20 virtual goods products IN TOTAL. Most services that rely on it for revenue have that many at release, let alone years down the road and long into maturity.